3 lbs. of any freshwater fish fillets (4 to 6 oz.) skin removed. 4 cups of distilled water. 1 cup of canning or pickling salt. 9 cups of distilled white vinegar, divided. 1 large red or white onion thinly sliced. 2 and 1/2 cups of sugar. 1/4 a cup, plus 1 table spoon mixed pickling spices. 1/4 a cup of bottle lemon juice or fresh strained lemon juice.
Freeze fish 48 hours at 0ºF. Defrost. Cut into 1 to 2 inch pieces. Set aside. In a large glass mixing bowl, combine water and pickling salt. Stir until salt is almost dissolved. Add fish, cover with plastic wrap. Refrigerate 2 days. Drain and discard brine. Rinse fish in cold water until rinse water is clear. Drain them completely.
In the same bowel, place fish and 4 cups of of white vinegar Cover with plastic wrap. Refrigerate 2 days. Drain and discard vinegar. Rinse fish in cold water until the rinse water is clear. Drain completely.
In three 1-quart jars or a gallon glass jar, loosely layer the fish with the onions in between. Cover and chill.
In a 2 quart saucepan, mix the remaining 5 cups of vinegar, the sugar, bay leaves and pickling spice. Bring mixture to a boil over a medium high heat, stirring constantly until the sugar is dissolved. Remove from heat, cool completely. Stir in the lemon juice. Pour the pickling liquid over fish covering them completely. Seal pickling jars, or if using a gallon glass jar, leave the lid a little loose. Refrigerate 4 to 5 days before serving. Do not store in refrigerator more than 4 weeks.